Trying to diagnose induction motor buzzing

[markba633csi]

Incidentally, there is a simpler, more elegant way to wire that style of drum switch (FYI):

 

[RJSakowski]

Incidentally, there is a simpler, more elegant way to wire that style of drum switch (FYI):
View attachment 309703

But it only works with a 220 volt wiring where the start winding is connected to the center of the two run windings circuit.

 

[AndySomogyi]

Thanks, I'll have to take a look at my drum switch when I get home, I think it connects the pins differently than yours. Yes, my motor does use the starter winding from the middle of the two main windings.

 

[markba633csi]

I believe you have what is called a "3 phase" reversing switch- it should match up
Your sketch has both ends of the start leg lifted and swapped, but in fact only one end needs to be flipped for the 240 volt configuration
Your motor is also an easier one to hook up since it doesn't have a thermal protector

 

[markba633csi]

Incidentally, the 3 components of the start leg (cent. switch, cap, winding) can be arranged in any order as long as they are in series, representing a two-terminal network (T5 and T8)
Electronix lesson for the day
Mr. Science is going back to his coffeepot now

 

[CluelessNewB]

If you have eliminated the possibility that the starting winding is not disengaging, other possibilities include:

1) Fan blade rubbing against something?
2) Did you mark the end bells when you disassembled? Did you put them back the same way?
3) Bearings and spacers put back in the same way they were originally?

 

[markba633csi]

What Clueless said and also: could the one of the cabinet walls be vibrating?

 

[hermetic]

That is LOUD!! I was going to suggest loose laminations in the motor, or even a loose stator coil, but that sounds for all the world like the noise a contactor makes rather than a motor, are you sure it is coming from the motor? has the contactor got the right voltage coil in it? the motor seems to run up to speed, and the cent sw sounds fine. Check that the centrifugal mechanmism has not moved on the shaft and is failing to open the contacts. The click you hear as the motor slows down is the centrifugal mechanism operating, not the switch contacts opening. as others have said, it does sound like the start winding is still in circuit, but louder than you would expect. Check the contactor if there is one.

 

[markba633csi]

Another important check you need to do is determine if any of the windings are shorted to each other or to the case. You would need to disconnect the motor leads and check using an ohmmeter or test lamp apparatus- probably a good idea to pull the motor and put it up on the bench for that
I just watched the video and I agree with Hermetic- something very wrong there based on the audio

 

[Z2V]

That is LOUD!! but that sounds for all the world like the noise a contactor makes rather than a motor, are you sure it is coming from the motor? has the contactor got the right voltage coil in it? Check the contactor if there is one.

I agree with @hermetic that it sounds like an unhappy contactor.
Can you feel any vibration in the motor while it’s got power on it?